For most vehicles with drum brakes all around or front disc and rear drum.
Absorbs water to protect the system from internal rust from pooling water.
Has a limited shelf life and why an open bottle should never be used.
Both DOT3 & DOT4 are hygroscopic and non-petroleum based.
DOT4
For most 4 wheel disc brake applications.
Absorbs less water then DOT3 and has a higher boiling point for 4 wheel disc systems that produce lots of heat.
DOT5
Silicone based - Has long shelf life but is not hygroscopic.
Can not be used with ABS systems or mixed with DOT3 or DOT4.
Will not damage painted surfaces.
High performance/heavy duty but must be flushed regularly to remove water.
